Software Open Access
This package contains some scripts written in the R language (R Core Team 2020) that allow the calculation of various morphometric methods published by Baur & Leuenberger (2011). Later these methods were addressed under the name "Multivariate Ratio Analysis (MRA)" (see Baur et al. 2014). The scripts were originally provided by the authors in an electronic supplementary file together with the original paper, and later in slightly modified form also by Baur et al. (2014). However, it is our wish to publish them in a manner that they may be cited separately and also be updated when necessary.
The package contains the main scripts in two files:
Important note: In the script of the LDA Ratio Extractor the case for more than 2 groups is now also included. This case was described by Baur & Leuenberger (2011, p. 817), but was left out from the R-script originally published in Systematic Biology. We think that the implementation is a welcome addition to the entire set of methods provided by MRA.
For both scripts, separate tutorials are available:
It is recommended to work through these brief tutorials, starting with the first one.
A dataset (from Baur et al. 2014) is supplied as well:
In order to avoid any troubles, make sure that all files are put into one and the same folder. R-Studio is recommended for performing the R-scripts (especially for beginners).
PDFs of the two papers cited below are also provided in the package.
Citation: You may use the citation of the package as indicated by Zenodo on this webpage. Do also cite the original paper by Baur & Leuenberger (2011, citation below), as only this article contains the mathematical background and scientific context concerning the methods.
Baur H, Kranz-Baltensperger Y, Cruaud A, Rasplus J-Y, Timokhov AV, Gokhman VE (2014) Morphometric analysis and taxonomic revision of Anisopteromalus Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) - an integrative approach. Systematic Entomology 39: 691–709. https://doi.org/10.1111/syen.12081
Baur H, Leuenberger C (2011) Analysis of ratios in multivariate morphometry. Systematic Biology 60: 813–825. https://doi.org/10.1093/sysbio/syr061
R Core Team (2020). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/.
Further reading (recommended examples of the use of MRA in taxonomy and functional morphology)
Huber C, Schnitter PH (2020) Nebria (Pseudonebriola) tsambagarav sp. nov., a new alpine species from the Mongolian Altai (Coleoptera, Carabidae). Alpine Entomology 4: 29–38. https://doi.org/10.3897/alpento.4.50408
Petrović TG, Vukov TD, Tomašević Kolarov N (2017) Morphometric ratio analyses: Locomotor mode in anurans. Comptes Rendus Biologies 340: 250–257. https://doi.org/10.1016/j.crvi.2017.02.004
Baur and Leuenberger - 2011 - Analysis of ratios in multivariate morphometry.pdf
Baur et al. - 2014 - Morphometric analysis and taxonomic revision of An.pdf